Balanced / Unbalanced Line Level to Unbalanced Guitar Level?

Started by fubusmaximus, December 30, 2003, 08:18:59 PM

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fubusmaximus

I've been looking for a schematic of a Balanced Line Level to Unbalanced Guitar Level box for a couple of weeks now, and the only schematic I've found is at:

http://www.jensen-transformers.com/as/as092.pdf

However, the transformer they suggest using is approx. $75 w/o shipping.  Is there any other alternatives to building a ReAmp box, with a cheaper, yet decent, transformer?  Or even a transformer-less design?

Nasse

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fubusmaximus

thanks for the links

brett

Balanced line level to unbalanced guitar level is very simple, as long as you don't mind unbalancing your line:
1. only use the "hot" balanced wire (that gives you unbalanced)
2. run that through a 1M log pot to ground.  From the wiper of the pot you can get anything from microphone level (a couple of mV) to line level (a couple of V).
You only need a more complicated system if you want noise-cancelling on your line input.
Hope that helps.
Brett Robinson
Let a hundred flowers bloom, let a hundred schools of thought contend. (Mao Zedong)

Eb7+9

Quote from: brett... need a more complicated system if you want noise-cancelling on your line input.
Hope that helps.

... you may want to use low resistance values to keep noise down ... a 22k resistor in series with a 1k pot (sweeper out) will give you a maximum output of little over 4% of your inut signal ... and at any point in the volume control rotation the Z to ground is no more than 1k - a low-noise standard in audio, this way you're not throwing away the advantage of an active output circuit ... if you find you don't get enough signal then lower the 22k value ...

... jc